Adjustable plunger



Mar. 27 1923.

I 1,449,791. D- L. STRINE.

ADJUSTABLE PLUNGER. FILED DEC-3- I921- Hit? Patented Mar. 27, 1923.

DOLPH LEE STRINE, F WINTERHAVEN, FLORIDA.

ADJUSTABLE PLUNGER.

Application filed December 3, 1921. Serial No. 519,601.

T 0 all whom it may concern Be it lmown that I, DOLPH LEE STRINE, acitizen of the United States of America, residing at Winterhaven, in thecounty of Polk and State of Florida, have invented certain new anduseful Improvements in Adjustable Plungers, of which the following is aspecification. i

This invention relates to pumps and has special reference to a piston orplunger for pumps of the reciprocating piston type.

One important object of the invention is to improve the generalconstruction of pump pistons.

It is a well understood fact that the cylinder walls of pumps,especially such pumps as are used for spraying and other purposes wherethe piston must fit tightly to obtaln the necessary pressure, becomerapidly worn. Consequently the piston no longer fits properly and leaks.

A second important object of the invention is to provide an improvedform of piston for pumps of this character which 3 may be expanded fromtime to time to compensate for wear on the pump cylinder.

In the wear of pump cylinders the enlargement of the cylinder due tosuch wear takes place at that part which is rubbed by the piston in itsreciprocation. The piston does not reciprocate under ordinary conditionsthroughout the entire length of the pump but there is a space at eachend which is not rubbed by such piston. Consequently any piston whichrequires withdrawal from the pump cylinder for the purpose of expansionor which cannot be put into the pump cylinder in a collapsed conditionand then expanded is ineffective to take up the wear.

A third very important object of the in-. vention is to provide animproved form of piston which may be expanded after insertionsufficiently into the pump cylinder to bring the cylinder wallcontacting part of the piston within the worn part of the cylinderbarrel.

A fourth important object of the invention-is to provide means for theabove purpose which may readily be operated byhand without requiring anytools whatever.

With the above. and other objects in view, the invention consists ingeneral of certain novel details of construction and combinations ofparts hereinafter fully described,

illustrated in the accompanying drawings, and specifically claimed.

In the accompanying drawings, like characters of reference indicate likeparts in the several views, and

Figure 1 is a side elevation of the improved pump piston removed fromthe pump.

Figure 2 is a vertical median section therethrough.

Figure 3 is a bottom plan view of the piston.

Figure 4 is a detail elevation of'the lower part of the piston with thecup packings shown in the foregoing figures removed.

Figure 5 is a detail section of a small part of the improved pistonshowing a modification of. certain elements thereof.

In-theembodiment of the invention herein illustrated there is provided ascrew 10 hav- 7 ing on its upper end a fork 11 through the arms of whichpasses a piVOt pin or bolt 12. This pivot pin or bolt also passesthrough the pump rod 13 sothat such rod is permitted to oscillate withreference to the screw 10 while the screw cannot rotate on its axis withrespect to the rod 13. Since the rod 13 .is held from rotation by itsconnection with the operating. mechanism of the pump in the usual-mannerthe screw will be also held from such rotation. The piston consists ofamain portion which comprises a hollow cylindrical body 14 threaded atits lower end as at 15 and in this threaded portion is screwed a plug 16having a screw threaded opening therein so that the body 14 and plug 16can be screwed together onto the screw 10. Surrounding the opening inthe plug 16 is a recess 17 wherein is carried a packing washer 18 toprevent leakage of fluid along the threads of thescrew. On the screw 10-in spaced relation to the piston body is mounted a disk 19 which is ofslightly less diameter than the shell 14 and on top of this disk is acup packing 20 which is preferably made of leather or the like in theusual way.. It willbe noted from Figure 2 that the shell 14 and plug 16have their lower ends beveled off as at 21 and the extremity of thisbeveled portion extends 105 downward through the cup packing 20. Thedisk 19, after it is screwed into position, is held against accidentalrotation by a suitable cotter pin 22 or other like device, the diskbeing slotted as at 23 at diametrically opposite points for thereception of the head of this pin.

It will now be obvious that rotation of the body of the piston to movethe same down along the screw will have the effectof torcing the sidewalls of the cup packing outward while rotation of the body in theopposite direction will permit collapse of said side walls. Beneath thedisk 19 is mounted a second cup packing 24 and in the hollow portion ofthis cup packing is a nut 25 of inverted frusto-conical form, the nutbeing held in position on the screw by a suitable pin 26.v Owing totheform of this nut whenever the piston moves downward the fluid beingpumped enters the space between he nut and the wall of the cup packing20 and expands the latter automatically.

In the torni of the device shown in Fig- ,ure 5 the plug 16 has nobeveled portion 21 as the bevel portion of the shell 14: extendsdownward to the bottom of the plug 16, the plug being simply screwedinto the shell 14 and not having any shoulder as shown in Fi ure 2.

in operation the lower end of the piston is inserted in the pumpcylinder, the plug 16 having been screwed up on the screw 10 as far asit will go. After the cup packings 20 .and 24: have reached a positionsufiiciently tar within the cylinder to bring them opposite thepart ofsuch cylinder as is contacted by these packing in operation, the part 14will project and this part is grasped by the hand and rotated to forceit downward into the cup packing 20 thus expanding the walls of thatpacking until they fit the cylinder to the required degree of pressure.The pump may then be operated in the usual way. As the cylinder wallswear or as the packing wears the piston is withdrawn sufticiently far toenable the part 14: to be grasped by the hand and this part is rotatedto force it further into the cup 20. In case the cup or cylinder 20becomes so badly worn that the cup will not, even when fully expanded,properly engage the cylinder wall the body of the piston is run up onthe screw and the entire piston withdrawn. The cup packings may then beremoved by first removing the nut 25, taking up the lower cup packing.removing the disk 19 and then removing the upper cup packing 20. New cuppackings may then be placed in position and the lQVlCG inserted in thecylinder and then expanded in the usual manner.

There has thus been provided a simple etficient device of the kinddescribed and for the purpose specified.

It is obvious that minor changes may be made in the form andconstruction of the invention without departing from the materialprinciples thereof. It is not therefore desired to confine the inventionto the exact form herein shown and described, but it is wished toinclude all such as properly come within the scope claimed.

Having thus described the invention, what is claimed as new, is 2- 1.111a pump piston, a stem, abody mounted on said stem, and a cup packingmounted on said stem, said stem and body being provided with coactingadjusting means operable by relative rotative movement of the stem andbody and arranged to force the cup packing to expand.

2. A pump piston including a threaded stem, a piston body screwed onsaid stem and rotatable thereon to move longitudinally thereof, saidbody having a tapered end, and a cup packing mounted in fixed positionon said stem, the hollow portion of said cup packing receiving thetapered end of the body whereby rotation of the body on the stem in onedirection will force said tapered end into the cup packing and therebyexpand the same.

3. A pump piston comprising a threaded stem, a piston body including anouter shell and a plug screwed onto said stem and into the lower end ofthe outer shell, said body having its lower end of invertedt'rustoconical torin, a cup packing mounted on said threaded stem andhaving its hollow,

portion toward the body, the tapered end of said body entering saidhollow portion," and a disk threaded on said stem below said packing tohold the latter against downward movement on the stem.

a. A pump piston comprising athreaded stem, a piston body including anouter shell anda plug screwed onto said stem and into the lower end ofthe outer shell, said body having its lower end of invertedfrustoconical form, a cup packing mounted on said threaded stem andhaving its hollow portion toward the body, the tapered end of said bodyentering said hollow portion, and a disk threaded on said stem belowsaid packing to hold the latter against dow nward movement of the stem,a second cup packing mounted on said SiZGDtlOGlOW the disk and facing inthe opposite direction to the first cup packing, and a nut screwed onsaid stem within the second cup packing.

5. A pump piston comprising a threaded stem, a piston body including anouter shell and a plug screwed onto said stem and into" the lower end ofthe outer shell, said body \aving its lower end of invertedfrustoconical form, a cup packing mounted on said threaded stem andhaving its hollow portion toward the body, the tapered'end of said bodyentering said hollow portion.

and a disk threaded on said stem below said" packing to hold the latteragainst downward movement of the stem, a second cup packing mounted onsaid stem below the disk and tacing in the opposite direction" to thefirst cup packing, and a nut screwed IOQLK on said stem within thesecond cup pack ing, said nut being of inverted frusto-conical formwhereby to provide a channel of triangular cross section between the nutand the side wall of the second cup packing.

6. A pump piston including a threaded stem, a piston body screwed onsaid stem and rotatable thereon to move longitudinally thereof, saidbody having its lower end reduced, and a cup packing mounted in fixedposition on said stem, the hollow portion of said cup packing receivingthe reduced end of the body whereby rotation of the body on the stem inone direction will force said reduced end into the cup packing andthereby expand the same.

7. A pump piston comprising a threaded Y stem, a piston body includingan outer shell screwed onto said stem and having its lower endreduced, acup packing mounted on the projecting portion of the threaded stem andhaving its hollow portion toward the shell, the reduced end of saidshell entering said hollow portion a disk threaded on said stem belowsaid packing, a second cup packing mounted on said stem below the diskand facing in the opposite direction to the first cup, and a nut screwedon saidstem within the second cup packing and arranged to provide achannel between said nut and the inner side wall of the second cuppacking.

In testimony whereof I aflix my signature.

DOLPH LEE STRINE.

